Vacuum Forming With 3D Printer Filament

December 11, 2021 by Tom Nardi 17 Comments

Even if they don’t have one themselves, we’d wager the average Hackaday reader is at least vaguely aware of how a vacuum former works on a fundamental level. You heat up a plastic sheet until it’s soft, then use a vacuum pump to pull the ductile material down onto an object and hold it there while it cools off. It’s easy to build a vacuum forming rig yourself, but small commercial units are cheap enough that it might not be worth your time. If everything goes to plan, the technique is a quick and effective way of duplicating items around the home and shop.

But we were recently tipped off to a variation of this classic technique that’s certainly worth further research. As demonstrated in a recent video, [Nathan Martinez] shows how 3D printed sheets can be used in place of the 5″ x 5″ squares of thermoplastic film that his imported vacuum former was designed to use. It’s easy enough to do: just model up a square with the appropriate 2D dimensions in your CAD package of choice, and extrude it to a height of about .5 mm.

A printed mesh pattern could be used to form custom shaped filters or strainers.

So what’s the advantage? Well for one thing, it’s cheaper. Though admittedly, not by much. Going rate on Amazon seems to be about 90 cents per sheet for the real stuff, and some back of the envelope math shows the printed version coming in at around 30 cents given nominal filament costs. Whether or not those savings are worth the extra effort is certainly debatable.

But that’s not really the most interesting part. With printed sheets loaded into the vacuum former, you’ve got access to a much wider array of materials to work with. For example, [Nathan] shows off some very interesting flexible pieces he was able to produce using sheets of TPU. You can also experiment with different surface textures. These can not only be used to give your vacuum formed pieces a bit of interesting visual flair, but could actually have some practical applications. In the video we see how a printed mesh could be formed over a piece to create a conformal air vent or filter.

To be sure, there’s some room for improvement here. Not all the pulls were successes, and [Nathan] says getting the printed sheets up to the proper temperature can be tricky. But when it works, it works quite well, and we think there could be some untapped potential in this unexpected melding of new and old methods of at-home plastic production.

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PetBot: Turn PET Bottles Into Filament

June 29, 2021 by Danie Conradie 44 Comments

Recycling plastic into filament normally involves chopping it into tiny pieces and pushing it through a screw extruder. [JRT3D] is taking a different approach with PetBot, which cuts PET bottles into tape and then turns it into filament. See the videos after the break.

Cutting the tape and extrusion happens in two completely separated processes on the same machine. A PET bottle is prepared by cutting off the bottom, and the open rim is pushed between a pair of bearings, where a cutter slices the bottle into one long strip, as a driven spool rolls it up. The spool of tape is then moved to the second stage of the machine, which pulls the tape through a hot end very similar to that on a 3D printer. While most conventional extruders push the plastic through a nozzle with a screw, the PetBot only heats up the tape to slightly above its glass transition temperature, which allows the driven spool to slowly pull it through the nozzle without breaking. A fan cools the filament just before it goes onto the spool. The same stepper motor is used for both stages of the process.

We like the simplicity of this machine compared to a conventional screw extruder, but it’s not without trade-offs. Firstly is the limitation of the filament length by the material in a single bottle. Getting longer lengths would involve fusing the tape after cutting, or the filament after extrusion, which is not as simple as it might seem. The process would likely be limited to large soda bottle with smooth exterior surfaces to allow the thickness and width of the tape to be as consistent as possible. We are curious to see the consistency of the filaments shape and diameter, and how sensitive it is to variations in the thickness and width of the tape. That being said, as long as you understand the limitations of the machine, we do not doubt that it can be useful. Continue reading “PetBot: Turn PET Bottles Into Filament” →

Fancy Filament Joiner Has Promise, But Ultimately Fails

December 17, 2020 by Lewin Day 29 Comments

[Proper Printing] has been trying to 3D print rims for his car for quite some time. However, the size of the print has led to problems with filament spools running out prior to completion. This led to endless headaches trying to join several smaller lengths of filament in order to make a single larger spool. After his initial attempts by hand failed, a rig was built to try and bring some consistency to the process. (Video, embedded below.)

The rig consists of a heater block intended to melt the ends of two pieces of filament so that they can be fused together. A cheap set of brass calipers was modified with a tube in order to form a guide for the filament, ensuring that it gets bonded neatly without flaring out to a larger size. Fan coolers are then placed either side of the heating area to avoid turning the whole filament into a hot mess.

Unfortunately, the rig simply didn’t work. The initial design simply never got the filament hot enough, with the suspicion being that heat was instead being dumped into the calipers instead of the filament itself. Modifications to reduce this sadly didn’t help, and in the end, more success was had by simply holding a lighter below a length of brass tube.

While the project wasn’t a success, there’s still value in the learning along the way. We can’t see any fundamental reason why such a rig couldn’t be made to work, so if you’ve got ideas on how it could be improved, sound off in the comments. We’ve seen other successful builds using hair straighteners in a relatively simple setup, too.

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Filament Dust Filter Helps Keep Your Print Quality High

September 6, 2020 by Lewin Day 19 Comments

If we’re honest, our workshop isn’t as clean as it probably should be, and likely many makers out there will say the same. This can have knock-on effects, such as iron filings clogging motors, or in this case, dust affecting the quality of 3D prints. Aiming to tackle this, [3Demon] built a fun Spongebob-themed dust filter for their 3D printer.

The filter works in a simple way. The Spongebob shell is 3D printed in two halves, with a hinge joining both parts. Inside each half, a section of sponge is stuck inside. The two halves are then closed with a snap fit, with the filament passing through a hole in Spongebob’s head and out through the (square) pants. With the sponge packed in nice and tight, dust is wiped from the filament as it feeds through bob to the printer.

While it’s important to install carefully to avoid filament feed issues, it’s an easy way to automatically clean filament during the printing process. You may be surprised just how dirty your filament gets after sitting on the shelf for a few months. Getting rid of such contamination decreases the likelihood of annoying problems like delaminations and jams. Avid printers may also want to consider making their own filament, too. Happy printing!

Testing Carbon Fibre Reinforced Filament By Building An Over-Engineered Skateboard

December 3, 2019 by Danie Conradie 4 Comments

Advances in filaments for FDM 3D printers have come in leaps and bounds over the past few years, and carbon fibre (CF) reinforced filament is becoming a common sight. Robotics extraordinaire [James Bruton] got his hands on some CF reinforced PLA, and ended up building a completely over-engineered 3D printed skateboard. (Video, embedded below.)

[James] started by printing some test pieces with a 0.5 mm and a big 1.2 mm nozzle with and without the CF, which he subjected to cantilever deflection tests. The piece with CF was 20% stiffer than without.

[James] then built an extremely strong and cool looking skateboard deck with alternating section of the CF PLA and toughened PLA, totalling 2.7 kg of filament. It was extremely strong, so after bolting on a set of trucks and wheels, he did some mild riding at a local skate park, where it survived without any problems. He admits it was completely over-engineered, but points out in that the internal cavities in the deck is the perfect place for batteries on an electric long board.

Designing something from the ground up with the strength and weaknesses 3D printing in mind, leads to some very interesting and innovative designs, of which this is a perfect example, and we hope to see many more like it. We’ve featured a number of [James]’ project, including the remote controlled bowling ball he built for [Mark Rober] and his impressive OpenDog and Start Wars robots.

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Slow Cooking Filament

June 3, 2018 by Al Williams 29 Comments

Getting good results from a 3D printer is like Goldilocks’ porridge. There are a lot of things that have to be just right. One common thing that gives people poor results is damp filament. This is especially insidious because the printer will work fine and then after some period time results degrade but it is no fault of the printer mechanics or electronics. There are many ways to attempt to dry filament, but [HydeTheJekyll] prefers using a slow cooker modified to operate with low air pressure.

We assume this works because the low pressure reduces the boiling point of water, allowing the water to boil off at temperatures that won’t distort the filament. The modifications aren’t very severe. You’ll need some hose and a pump along with some silicone caulk and petroleum jelly.

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Bent PETG Fills A Nixie Gap

April 19, 2018 by Drew Risinger 21 Comments

Have you ever thought that Nixie tubes are cool but too hard to control with modern electronics? And that they’re just too expensive? [david.reid] apparently thought so and decided to create his own version of a Nixie tube, and it doesn’t get much cheaper than this.

While working on a 3D printed locomotive with his son, [david.reid] used clear PETG (Polyethylene Terephthalate Glycol) 3D printer filament to move light from LEDs to various parts of the locomotive. He found this was a success, but roughed up the outside of the filament to see what would happen. Lo and behold, a warm glow appeared on the surface of the tube! Like any good hacker, his next thought was of Nixie tubes, as you have seen in many clocks.

His basic idea is that with a little heat you can bend the filament into any shape that you like ([david.reid] uses custom molds). You then use some sandpaper to roughen up the outside wherever you’d like light to show, and add an LED at the bottom to light it up!

[david.reid] isn’t the first person to modernize Nixie Tubes. Over the years, we’ve seen them combined with Wi-Fi boards, individual LED segments, or even laser cutters & WS2812s!

Now’s a great time to get started on a project for the Hackaday Prize! If you’re looking for somewhere to start, we’d love to at least see your own take on a clock!